The present invention relates to an electrical connector system having movably mounted contacts to accommodate misalignment between male and female connector parts.
Fuel cells are electrochemical systems, which convert the chemical energy from oxidation processes directly into electrical energy. This electrical energy has to be forwarded to the various devices via the power supply unit. In mobile applications in particular, the connection between fuel cell and power supply unit must occupy a minimum amount of space. In applications requiring a plurality of connectors, the male connector parts are generally mounted on the power supply unit and the female connector parts on the fuel cell. The respective manufacturing tolerances may however create positional variational or misalignment between male connector parts and female connector parts, which lead to damage to the connector. At the same time, due to the extremely harsh environmental conditions, the connector assemblies are required to withstand vibration, corrosion, and heat while maintaining current carrying capacity. In addition, the connection has to be capable of being frequently released and reliably reconnected with low insertion force.
Since the output voltages supplied by the fuel cell are direct current voltages of up to approx. 800 volts, the contact socket should be automatically closed in an unmated condition to avoid unintentionally inserted items.
An object of the present invention is therefore to provide an electrical connector which compensates any offset or misalignment between female connector part and male connector part resulting from manufacturing tolerances without damage thereto during mating. A further object with such connectors is to protect the contact socket from unintentional contact when the contact pin is not inserted therein.
The invention provides an electrical connector having a male connector part having a contact pin and a first base member, a female connector part having a contact socket and a second base member. The contact pin is insertable into the contact socket in order to effect electrical connection between the male connector part and the female connector part. At least one of the contact pin or the contact socket are mounted movably in the respective base member and precentred in the respective base member by means of a spring via a centring bevel, which is provided on the respective base member.
According to an embodiment of the invention, the contact pin has an insertion bevel at the end. The centring process during insertion of the contact pin into the contact socket is thereby simplified.
If an insertion cone is provided at the end of the contact socket, the centring process during insertion may be further simplified.
A particularly flexible, economic option for achieving movable mounting consists in mounting the contact pin and/or the contact socket in the respective base member with adequate play.
In order to achieve a central starting position for the movably mounted contact pin and/or contact socket, the contact pin and/or the contact socket may be precentred in the respective base member by means of a spring or a centring bevel, which is provided on the respective base member. Particularly suitable for this purpose is an angle of approx. 10xc2x0 between the centring bevel and the cross-sectional plane of the connector.
According to another embodiment, the first base member and/or the second base member comprise(s) retaining projections on an inner side which interact with corresponding projections on the contact pin and/or the contact socket to prevent axial displacement of the contact pin and/or the contact socket. It is thereby ensured that the contact pin and/or the contact socket has/have sufficient mechanical stability for fitting together and release of the electrical connection.
In another embodiment of the invention, the connector assembly, it may be ensured that the contact socket is secured in the open state against undesired contact and the contact pin may easily open this securing means upon closure of the electrical connection. To this end, the contact pin comprises an insertion bevel, which exerts uniform, radially outwardly directed mechanical pressure on the closing element and thereby releases it.
According to another embodiment, the closing elements are held by a spring in the closed state when the contact pin is not inserted. It may thereby be ensured that the contact socket of the open electrical connector is always automatically protected against unintentional contact.
Particularly precise adjustability of the required spring forces is achieved by using a shaped wire spring. On the other hand, the use of a worm spring is particularly simple with regard to construction, since in this case only a simply produced annular receptacle needs to provided on the outside of the contact insulation to fix the spring in place.
Additional security against the penetration of very thin wires (diameter 1 mm, see IEC 529) is provided by an embodiment in which the female part of the electrical connector comprises a further closing element, which closes the contact socket and may be displaced in the axial direction once the contact pin has released the closing elements.
In order to bring this closing element also automatically into its securing position, as soon as a contact pin is no longer inserted, this further closing element may likewise be held by means of a spring.
According to another embodiment, the contact pin comprises a contact member and an insertion cap separate therefrom. In this way, it may be ensured that the insertion bevel, which is under particular mechanical stress during insertion of the contact pin, may be made of a particularly suitable material, which exhibits relatively poor electrical characteristics, however. In this embodiment, the actual contact member which produces the electrical connection may be made of the material best fulfilling these requirements.
By providing the contact socket with a contact tube and a separate locating bush, the contact pin is additionally centred by the locating bush and relatively large transverse forces are not transmitted to the contact tube but rather are absorbed by the locating bush.
Depending on the requirements made of the electrical connector, the respective features involved in movable mounting of contact pin and/or contact socket and in securing of the contact socket against unintentional contact may be used alone or in combination.